JP4684349B2 - Relay node - Google Patents

Description

  The present invention relates to a technique for acquiring path trace information in a GMPLS (Generalized Multi-Protocol Label Switching) / MPLS (Multi-Protocol Label Switching) network.

  First, the path establishment signaling protocol used in the GMPLS / MPLS network and GMPLS / MPLS will be briefly described. Then, a conventional route trace method will be described.

(GMPLS / MPLS)
GMPSL / MPLS is a technology for transferring data according to label information. The label information corresponds to a fixed length label attached to the head of a packet, a time slot for time division transmission, an optical wavelength in optical multiplex transmission, and the like. In particular, a network that transfers data using a fixed-length label attached to the head of a packet is called an MPLS network. Note that in the GMPLS network, some or some of the label information including the fixed length label used in the MPLS network is used.

  For example, in packet transfer using a fixed-length label, a relay node (LSR: Label Switched Router) holds a label table indicating a relationship between an output label and an output IF for an input label and an input IF (Interface). At the time of packet relay, the output IF is determined according to the label attached to the received packet instead of the address, and the label attached to the packet is rewritten and relayed to the output label. By repeating this, the packet is transmitted to the destination. A relay node (starting node) at the entrance of the GMPLS / MPLS network first attaches a label. This is a high-speed packet relay technology.

  FIG. 21 is a diagram for explaining the packet relay method. Here, the packet is transferred from LSR1 to LSR4. First, LSR1 attaches label a to the packet to be transferred. When the LSR 2 receives a packet having the label a from IF # 1, the LSR 2 searches the label table and acquires the output IF and the output label. Then, after rewriting the label of the packet to the output label, the packet is output to the output IF. This is repeated and the packet is transferred to the terminal LSR 4 (end node). By transferring according to the fixed-length label in this way, it is possible to increase the speed of packet relay.

  Further, by associating bandwidth control with each label at the relay node, bandwidth guarantee can be performed for each packet flow.

  In time division transmission, each node holds a label table that indicates the relationship between the output time slot and the output IF with respect to the input time slot and the input IF (interface). Each node determines an output IF and an output time slot according to the reception IF and the reception time slot, and outputs data to the output time slot of the output IF. By repeating this, data is transmitted to the destination.

  In the optical multiplex transmission, each node holds a label table indicating the relationship between the input optical wavelength and the output optical wavelength and the output IF with respect to the input IF (interface). Each node determines an output IF and an output optical wavelength according to the reception IF and the reception optical wavelength, converts the reception optical wavelength into an output optical wavelength, and outputs the output optical wavelength to the output IF. By repeating this, data is transmitted to the destination.

  GMPLS is a technique for performing transfer with the same mechanism by treating fixed-length labels, time slots, and optical wavelengths as labels as described above.

(Path establishment signaling protocol (RSVP-TE: Resource reSerVation Protocol-Traffic Extension))
FIG. 22 is a diagram illustrating the operation of the path establishment signaling protocol.

  In GMPLS / MPLS, it is necessary to construct a label table at each node. For this purpose, a path establishment signaling protocol (such as CR-LDP (Constraint-based Routing Label Distribution Protocol) / RSVP-TE) as shown in FIG. 22 is used.

  Hereinafter, taking RSVP-TE as an example, the operation of establishing a path by constructing a label table will be described. The start node requesting path establishment transmits a path establishment request message (Path message) to the end node of the path by Hop-by-Hop. In the example of FIG. 22, in order to explicitly specify a route, information on a relay node that is routed is inserted into the Path message. The end point node that has received the Path message returns a path establishment response message (Resv message) for assigning a label to the start point node along the path through which the Path message has been sent. At this time, a label table for transferring data is constructed by registering the label stored in the Resv message in the label table. A path ID is stored in both the Path / Resv message, and the path ID is also registered in the label table.

(Conventional route trace information acquisition method RRO)
FIG. 23 is a diagram illustrating an operation of a route trace function using RRO (Record Route Object).

  Hereinafter, a conventional method for realizing the path trace function will be described by taking RSVP-TE as an example. A technique using RRO is defined in the IETF standard as a technique for realizing a path trace in RSVP (Non-patent Documents 1 and 4).

  The operation will be described below (FIG. 23). The source node that requests the route trace inserts an object RRO for requesting the route trace into a path establishment request (Path) / response (Resv) message for establishing a path, and has its own node identifier as an RRO sub-object. And a path establishment request message (Path message) is transmitted by Hop-by-Hop. The intermediate node that has received the Path message determines that the path trace function is enabled because the RRO object is inserted, and adds its own node identifier to the list as an RRO sub-object, and then the Path message. Is transferred to the next hop. Each intermediate node performs this procedure, and finally, the RRO including the list of nodes through which the Path message has passed is carried to the end node by the Path message. The end node that has received the Path message inserts a RRO object and a sub-object including its own identifier into a response (Resv) message, and returns it to the start point node along the path through which the Path message has been sent. The intermediate node that has received the Resv message including the RRO sub-object adds its node identifier to the list as the RRO sub-object, and then transfers the Resv message to the next hop. Eventually, the RRO including the list of nodes through which the Resv message has passed is carried to the start node by the Resv message. By executing the above procedure, each node obtains a list of nodes located upstream from the Path message and a list of nodes located downstream from the Resv message, and is established from both information. It is possible to obtain information on the nodes through which the path has passed.

FIG. 24 is a diagram showing the standard specification processing flow described above. When each relay node receives a path establishment request (or response), each relay node checks whether or not there is a route recording request (RRO) in the message. When there is a route record request, the identifier of the own node is added to the route information list, and a path establishment request (or response) is transmitted to the next node. When there is no route storage request, a path establishment request (or response) is transmitted to the next node as it is.
JP 2000-244563 A D. Awduche, L. Berger, D. Gan, T. Li, V. Srinivasan, G. Swallow, “RSVP-TE: Extensions to RSVP for LSP Tunnels.” Network Working Group Request for Comments (RFC) 3209, December 2001 . P. Ashwood-Smith, Ed., L. Berger, Ed., “Generalized Multi-Protocol Label Switching (GMPLS) Signaling Constraint-based Routed Label Distribution Protocol (CR-LDP) Extensions.” Network Working Group Request for Comments (RFC ) 3471, January 2003. L. Berger, Ed., “Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions.” Network Working Group Request for Comments (RFC) 3473, January 2003. K. Kompella, Y. Rekhter, “Signalling Unnumbered Links in Resource ReSerVation Protocol-Traffic Engineering (RSVP-TE).” Network Working Group Request for Comments (RFC) 3477, January 2003. J. Moy, “OSPF Version 2.” Network Working Group Request for Comments (RFC) 2328, April 1998. D. Katz, K. Kompella, D. Yeung, “Traffic Engineering (TE) Extensions to OSPF Version 2.” Network Working Group Request for Comments (RFC) 3630 September 2003. K. Kompella, Ed., Y. Rekhter, Ed., “Routing Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS).” Network Working Group Request for Comments (RFC) 4302, October 2005. K. Kompella, Ed., Y. Rekhter, Ed., “OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS).” Network Working Group Request for Comments (RFC) 4303, October 2005.

  FIG. 25 is a diagram illustrating a problem of an existing route trace.

  In a network in which a plurality of network domains are connected, when each domain is for each carrier, etc., it is necessary to conceal the information in the domain. In order to avoid a DOS attack (Denial of Service attack) and the like on the Internet, a mechanism is adopted in which information in the carrier network is not disclosed to the outside as much as possible.

  On the other hand, in the GMPLS / MPLS network, when RRO is used to acquire route trace information, it is defined as a rule that each node places its own node ID on the RRO sub-object and transfers it to an adjacent node. This mechanism has the following problems when you do not want to disclose information within a certain network range (domain) to the outside. As a result, it is possible to easily extract information within a domain from an external domain. (FIG. 25).

  (1) It is impossible to know a boundary with a network where information should not be disclosed.

  (2) Of the route information described in the route trace information, it is not possible to specify information that is a target for hiding information.

  (3) The route information described in the route trace information cannot be deleted.

  FIG. 26 is a diagram illustrating an operation when the RRO function is disabled. When a path message including RRO is transmitted from node A, an error indicating that RRO is not supported is returned to node A from node D, which is an RRO non-implemented node. Node A establishes a path by sending a path message that does not include the RRO.

  In this way, when it is not desired to disclose information, the outflow of information outside the domain can be prevented by making the nodes in the domain incompatible with RRO (FIG. 26). However, since the function of obtaining route trace information itself becomes invalid, it is necessary to take a method different from the existing mechanism when obtaining route information in the domain.

  Accordingly, an object of the present invention is to provide a relay node that does not disclose information on a specific node while maintaining a function for acquiring route trace information.

  The present invention employs the following means in order to solve the above problems.

That is, the present invention
A receiving unit that receives a path trace control message including path information related to a path used for data transfer from a start point node to an end point node from a previous node on the path;
When the own node is a boundary node located at the boundary of the route information shielding section on the path, the portion related to the route information shielding section of the route information included in the route trace control message received by the receiving unit is identified. An editorial department that edits in an impossible state,
A sending unit that sends the edited route trace control message to a next node located on the path;
Are relay nodes.

  According to the present invention, it is impossible to recognize information related to the route information in the route information shielding section from the nodes outside the route information shielding section in the route information.

Preferably, in the present invention,
The editing unit is a relay node that adds pseudo information related to the route information shielded section to the route information instead of the part related to the deleted route information shielded section.

  According to the present invention, it is possible to conceal information related to a route information shielding section while maintaining a route trace information acquisition function.

  According to the present invention, by adding pseudo information, an existing route information acquisition function and interconnectivity are guaranteed.

Preferably, in the above invention,
The route information includes a list having an identifier of a node through which the path passes and a flag indicating whether the node belongs to the route information shielding section,
The editing unit identifies a node belonging to the route information shielding section in the list based on the flag, and sets an identifier of the identified node as a relay node that is deleted from the list.

  According to the present invention, the information on the nodes belonging to the route information shielding section is not included in the route information transmitted outside the route information shielding section.

  According to the present invention, it is possible to prevent outflow of route information outside the route information shielding section.

Preferably, in the above invention,
Link management information database that stores the domain to which the local node belongs and the domain to which other relay nodes connected to the local device belong,
Further comprising
The editing unit
Referring to the link management information database, determine whether or not the domain to which the own device belongs and the domain to which the second relay node that is the transmission destination of the control message matches,
When the domain to which the own node belongs does not match the domain to which the next-stage relay node device that is the transmission destination of the control message does not match, the relay node determines that the own node is the boundary node .

  According to the present invention, the link management information database can appropriately determine whether or not the own node is a boundary node.

Preferably, in the above invention,
When the own node is not the boundary node and belongs to the route information shielding section, the editing unit includes an identifier of the own node and the own node including the route information in the route trace control message received by the receiving unit. A relay node to which a flag indicating belonging to the shielded section is added.

  According to the present invention, by adding a flag, it is possible to appropriately determine whether or not the relay node included in the route information belongs to the route information shielding section at the boundary node.

  Here, the “editing unit” in the present invention includes an RRO processing unit. The “storage unit” in the present invention includes a shielding target node database.

  According to the present invention, it is possible to provide a relay node that does not disclose information on a specific node while maintaining a function for acquiring route trace information.

FIG. 1 is a diagram illustrating shielded area designation based on the domain of the first embodiment. FIG. 2 is a diagram illustrating a configuration of a node according to the first embodiment. FIG. 3 is a diagram illustrating the node 10F (domain 2, in the shielding area) link management information database. FIG. 4 is a diagram illustrating a processing flow of the first embodiment. FIG. 5 is a diagram illustrating provision of a shielding target flag. FIG. 6 is a diagram illustrating sub-object deletion processing by a boundary node. FIG. 7 is a diagram illustrating RRO IPv4 address sub-object (Type 0x01). FIG. 8 is a diagram illustrating RRO Unnumbered Interface ID sub-object (Type 0x04). FIG. 9 is a diagram illustrating processing by a Resv message. FIG. 10 is a diagram illustrating designation of an arbitrary shielding range. FIG. 11 is a diagram illustrating the node 20C (domain 1, in the shielding area) link management information database. FIG. 12 is a diagram illustrating partial shielding of route information. FIG. 13 is a diagram illustrating an example of a network configuration according to the third embodiment. FIG. 14 is a diagram illustrating a processing flow of the third embodiment. FIG. 15 is a diagram illustrating pseudo node addition processing. FIG. 16 is a diagram illustrating an example of a node configuration according to the fourth embodiment. FIG. 17 is a diagram illustrating a processing flow according to the fourth embodiment. FIG. 18 is a diagram illustrating a specific example of a shielding target node by data matching. FIG. 19 is a diagram illustrating a processing flow of the fifth embodiment. FIG. 20 is a diagram illustrating a specific example of a shielding target node by data matching. FIG. 21 is a diagram illustrating packet transfer using a fixed-length label. FIG. 22 is a diagram illustrating the operation of the path establishment signaling protocol (RSVP-TE). FIG. 23 is a diagram illustrating the operation of the path trace function using RRO. FIG. 24 is a diagram showing a standard specification processing flow. FIG. 25 is a diagram illustrating a problem of an existing route trace. FIG. 26 is a diagram illustrating an operation when the RRO function is disabled.

Explanation of symbols

10, 10A-10I node
20, 20A-20M node
30, 30D-20I node
100 network
200 Network 1012 Data Receiving Unit 1014 Data Relay Unit 1016 Data Transmitting Unit 1022 Control Packet Receiving Unit 1024 Path Control Unit 1026 Control Packet Transmitting Unit 1030 RRO Processing Unit 1052 Link Management Information Database 1054 Shielding Target Node Database 1056 Label Table

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The configuration of the embodiment is an exemplification, and the present invention is not limited to the configuration of the embodiment. In addition, the embodiments can be configured by appropriately combining the embodiments.

[Embodiment 1]
<Constitution>
FIG. 1 is a diagram illustrating a network configuration example according to the present embodiment. FIG. 1 is an example when the shielding target area of the route information is set in units of domains.

  Regardless of the domain, an arbitrary range can be used as the shielding target area of the route information, and the domain can be re-divided according to the shielding target area.

  In the network 100 of FIG. 1, there are nine nodes (nodes 10A to 10I). Node 10A, node 10B, and node 10C are included in domain 1, node 10D, node 10E, and node 10F are included in domain 2, and node 10G, node 10H, and node 10I are included in domain 3. Here, the domain 2 is set as a shielding target area of the route information. In this case, the node located at the boundary of the shielding target region recognizes that the own node is the shielding boundary node using the domain attribute information (link management information database) of the link. Here, links within the domain are defined as intra-domain links, and links connecting the domains are defined as inter-domain links. Each node manages a link (link attribute) directly connected to its own node.

  FIG. 2 is a diagram illustrating an example of a configuration of a shielding target node of route information according to the present embodiment. The nodes in the shielding target area of the route information in this embodiment are the data reception unit 1012, the data relay unit 1014, the data transmission unit 1016, the control packet reception unit 1022, the path control unit 1024, the control packet transmission unit 1026, and the RRO processing unit. 1030, a link management information database 1052, and a label table 1056.

  The data receiving unit 1012 receives data from the adjacent node, and transmits the data to the data relay unit 1014 to determine the destination.

  The data relay unit 1014 receives data from the data receiving unit 1012. The data relay unit 1014 refers to the label table 1056 and determines the destination of the data received from the data receiving unit 1012. The data relay unit 1014 attaches the label written in the label table 1056 to the data, and transmits the data to the data transmission unit 1016.

  The data transmission unit 1016 receives data from the data relay unit 1014. The data transmission unit 1016 transmits the data to which the label is assigned to the adjacent node.

  The control packet receiving unit 1022 receives a control packet for establishing or deleting a path from an adjacent node. The control packet receiving unit 1022 transmits the control packet to the path control unit 1024.

  The path control unit 1024 receives a control packet from the control packet receiving unit 1022. The path control unit 1024 performs label allocation for path establishment in response to a request for the control packet. The path control unit 1024 registers the assigned label information in the label table 1056. The path control unit 1024 rewrites the contents of the control packet to be used for transmitting to the next adjacent node as necessary. The path control unit 1024 transmits the control packet to the control packet transmission unit 1026. Further, the path control unit 1024 transmits the control packet to the RRO processing unit 1030 when the RRO request is included in the control packet. This is because the RRO processing unit 1030 performs control packet processing.

  The RRO processing unit 1030 receives a control packet including an RRO request from the path control unit 1024. The RRO processing unit 1030 performs a record route object (RRO) entry addition process. That is, the RRO processing unit 1030 adds the RRO sub-object including the identifier of the own node to the RRO. In addition, the RRO processing unit 1030 gives a shielding target flag indicating that the RRO sub-object is a shielding target node to the RRO. Further, the RRO processing unit 1030 performs a shielding boundary node determination process, a shielding target route information specifying process, and a shielding target route information deletion process. The RRO processing unit 1030 includes the processing result in the control packet and transmits the control packet to the control packet transmission unit 1026.

  The control packet transmission unit 1026 receives a control packet from the path control unit 1024 or the RRO processing unit 1030, and transmits the control packet to the adjacent node.

  The link management information database 1052 stores corresponding destination domain information for each interface of the own node. Further, the link management information database 1052 stores information on a domain (own domain) to which the own node belongs. By comparing the destination domain of a specific interface with the domain to which the own node belongs, it is possible to determine whether the connection destination node of the link of the specific interface is inside or outside the domain.

  FIG. 3 is a diagram illustrating an example of the link management information database of the node 10F. Each node has a link management information database 1052. The link management information database 1052 includes information on the domain to which the own node belongs (own domain) and information on the destination domain for each interface. In the node 10F, the node 10F itself belongs to the domain 2, and the domain 2 is connected to the interface # 1, and the domain 3 is connected to the interface # 2. From this, it can be determined that the interface # 1 of the node 10F is an intra-domain link, and the interface # 2 of the node 10F is an inter-domain link.

<Operation example>
FIG. 4 is a diagram illustrating an example of a processing flow of a node in the shielding target area in the present embodiment. Here, description will be given mainly using the node 10F as an example. The same processing flow is used in the node 10D and the node 10E.

  Here, using the path establishment signaling protocol (RSVP-TE), from the node 10A to the node I through the node 10B, the node 10C, the node 10D, the node 10E, the node 10F, the node 10G, and the node 10H in order. Establish a path for the route. The starting node 10A requests a path trace by including RRO in the Path message in the path establishment request.

  The node 10F receives a path establishment request from the adjacent node (FIG. 4: S1002). The node 10F confirms whether or not the path establishment request is a Path message including RRO (S1004). If the path establishment request is a Path message that does not include RRO (S1004; NO), the path establishment request is transmitted to the next node after predetermined processing (S1018). When the path establishment request is a Path message including RRO (S1004; YES), an ordinary path establishment process is executed and an RRO sub-object including the identifier of the own node is added to the route information list (S1006, RRO processing) ). The node 10F gives a flag indicating that the RRO sub-object is a shielding target (S1008).

  FIG. 5 is a diagram illustrating an example of providing a shielding target flag. In the node 10D, the node 10E, and the node 10F, together with the RRO sub-object including the identifier (D, E, or F) of the own node, the shielding target flag (1) indicating that the RRO sub-object is a shielding target. Is granted.

  Next, the node 10F specifies an interface to which a Path message should be sent. Information for specifying this interface can be obtained by performing route calculation by itself using information on the end point of the path. Further, when an Explicit Route Object for specifying a route is included in the Path message, it is obtained according to the description.

  The node 10F determines whether or not the own node is a node located on the shielding boundary (FIG. 4: S1010, shielding boundary node determination processing). The node 10F compares the information of its own domain in the link management information database 1052 with the information of the destination domain of the interface that transmits the Path message, and determines whether or not its own node is located at the shielding boundary.

  Here, for example, in the case of the node 10D (or the node 10E), the information of its own domain matches the information of the destination domain (FIG. 4: S1010; NO). At this time, the node 10D (or the node 10E) determines that the own node is not located at the shielding boundary, and transmits a path establishment request to the next node after predetermined processing (S1018).

  In the case of the node 10F, the information of its own domain and the information of the destination domain do not match (FIG. 4: S1010; YES). At this time, the node 10F determines that the own node is located at the shielding boundary and performs the following process. The node 10F refers to a flag indicating that the RRO sub-object is a shielding target, and identifies shielding target route information (information of a node that is a shielding target) (S1012, identification processing of shielding target route information). It is determined that the RRO sub-object to which the flag indicating the shielding target is given is the shielding target route information. The node 10F deletes the RRO sub-object determined to be shielding route information from the list (S1014, shielding target route information deletion processing). The node 10F transmits a path establishment request to the next node after predetermined processing (S1018).

  The node 10F determines whether or not the own node is a shielding boundary node before giving the shielding target flag. If the node 10F determines that it is a shielding boundary node, the node 10F adds an RRO sub-object including the identifier of the own node and You may make it the structure which does not provide the shielding target flag.

  FIG. 6 is a diagram illustrating an example of RRO sub-object deletion processing by a boundary node. When the node 10F determines that the own node is a shielding boundary node, the node 10F deletes the RRO sub-object (D, E, F) to which the flag indicating that it is a shielding target and the flag are assigned.

  7 and 8 are diagrams illustrating examples of sub-objects defined in the standard. FIG. 7 shows Type 0x01 IPv4 address sub-object, and FIG. 8 shows Type 0x04 Unnumbered Interface ID sub-object.

  When Type 0x01 IPv4 address sub-object in FIG. 7 is used, a node identifier is assigned to IPv4 address. When Type 0x04 Unnumbered Interface ID sub-object in FIG. 8 is used, the node ID is assigned to Router ID, and the interface number that received the Path message including RRO in Interface ID or the Path message including RRO is transmitted. Assign an interface number. The shielding target flag can be realized by defining a new value in Flags. The already defined Flags are:

0x01 Local protection available
0x02 Local protection in use
When Type 0x04 Unnumbered Interface ID sub-object in FIG. 8 is used, a new flag may be defined in the Reserved area to be a shielding target flag.

  FIG. 9 is a diagram illustrating an example when a Resv message of a path establishment response is used. It is assumed that the domain 2 including the node 10D, the node 10E, and the node 10F is a shielding target area.

  The node 10F that has received the Resv message whose path establishment response includes RRO from the node 10G executes the normal path establishment process and performs the RRO process. The node 10F adds an RRO sub-object including the identifier of the own node to the RRO and assigns a shielding target flag indicating that the RRO sub-object is a shielding target. Next, the node 10F specifies an interface to which a Resv message should be sent. This information is obtained by referring to the Path State generated in the node when the Path message is received and transmitted. After the interface to be sent (# 1 in this case) is obtained, it is checked against link attribute information (link management information database 1052) managed by the own node, and whether the interface is an intra-domain link or an inter-domain link Judging. In the case of the node 10F, since the interface # 1 to which the Resv message is to be sent next is an intra-domain link, it is determined that the own node is not a shielding boundary node. The node 10F, which is a node other than the shielding boundary node, performs Resv message transmission processing. Similar processing is also performed in the node 10E.

  On the other hand, the node 10D that has received the Resv message whose path establishment response includes RRO from the node 10E executes the normal path establishment process and performs RRO processing. The node 10D adds an RRO sub-object including the identifier of the own node to the RRO and assigns a shielding target flag indicating that the RRO sub-object is a shielding target. The node 10D determines whether or not the own node is a shielding boundary node. Since the interface # 1 to which the node 10D should next send the Resv message is an inter-domain link, the node 10D determines that its own node is a shielding boundary node. The node 10D that is the shielding boundary node refers to the list of RRO sub-objects and deletes the RRO sub-object to which the shielding target flag is assigned from the list. Thereafter, RRO is stored in the Resv message and sent to interface # 1.

<Effect of Embodiment 1>
According to the present embodiment described above, it is possible to obtain normal route information in the shielding target area without disclosing the route information of the shielding target area to each node outside the shielding target area. For example, the node 10G outside the shielding target area acquires the upstream route information {A, B, C} from the Path message, and the downstream route information {H, I} from the Resv message. The path information {A, B, C, G, H, I} of the path is obtained from the combination of the information and the information of the own node. This is a format in which the route information {D, E, F} in the shielding target area is concealed. On the other hand, in the node 10E in the shielding target area, upstream route information {A, B, C, D} is obtained from the Path message, and downstream route information {F, G, H, I} is obtained from the Resv message. To do. The path information {A, B, C, D, E, F, G, H, I} of the path is obtained from the combination of this information and the information of the own node. This is route information including all nodes on the path.

(Modification)
FIG. 10 is a diagram illustrating a configuration example of a network in a modified example of the present embodiment. FIG. 10 shows an example in which the shielding target area of the route information is arbitrarily set regardless of the domain.

  In the network 200 of FIG. 10, there are 13 nodes (nodes 20A to 20M). Node 20A, Node 20B, Node 20C and Node 20N are in Domain 1, Node 20D, Node 20E, Node 20F and Node 20J are in Domain 2, Node 20G, Node 20H and Node 20I are in Domain 3, Node 20K and Node 20L And the node 20M is included in the domain 4.

  Here, a region surrounded by a dotted line in FIG. 10 is set as a shielding target region of the route information. That is, it is assumed that the node 20A, the node 20B, the node 20C, the node 20D, the node 20E, the node 20F, the node 20J, the node 20K, and the node 20M are nodes within the shielding target area. The shielding target area of the route information includes a part of domain 1 and domain 4 and domain 2. Each node in the shielding target area holds link attribute information (link management information database) for identifying the shielding target area.

  At this time, the link connecting the node 20C and the node 20N is an intra-domain link of the domain 1, and is a link connected outside the shielding target area of the route information.

  Each node of the modification of the present embodiment has a configuration similar to that of the node shown in FIG.

  FIG. 11 is a diagram illustrating an example of a link information management database held by the node 20C. Each node has a link management information database 1052. The link management information database 1052 includes information on a domain to which the own node belongs (own domain), information on a destination domain for each interface, and information indicating whether the destination node is within or outside the shielding target area. In this case, prohibition of information disclosure outside the shielding target area is set as the route information shielding policy. In the link management information database 1052, information on the domain (own domain) to which the own node belongs is not always necessary.

  Each node in the shielding target area of the route information can recognize whether or not the own node is located at the shielding boundary node based on the link management information database, and can perform an appropriate process.

  Each node in the shielding target area of the present modification performs the same processing as the processing flow shown in FIG. However, whether or not the own node is located at the shielding boundary is determined based on whether the destination node of the link management information database 1052 is inside or outside the shielding target area. If the destination node is outside the shielding target area, it is determined that the node is located at the shielding boundary.

[Embodiment 2]
Next, Embodiment 2 of the present invention will be described. The second embodiment has common points with the first embodiment. Therefore, the difference will be mainly described, and the description of the common points will be omitted.

  In the present embodiment, a method for shielding the route information of only some nodes in the shielding target area of the route information will be described.

<Constitution>
The network configuration of the present embodiment is the same as the network configuration example of FIG. The configuration of each node in the shielding target area of the route information of this embodiment is the same as the configuration of the node of FIG. 2 in the first embodiment.

  Further, as a modification, a network configuration similar to that in FIG. 10 in the modification of the first embodiment may be used.

<Operation example>
The processing flow of each node in the shielding target area of the route information is the same as the processing flow of FIG. 4 of the first embodiment. In the first embodiment, the shielding target flag indicating that the RRO sub-object is the shielding target is uniformly given to each node in the shielding target area. In the present embodiment, a shielding policy can be set for each node. When the shielding asymmetric policy is set for a certain node, the shielding target flag is not added when adding the RRO sub-object. With this configuration, a node for which the shielding asymmetric policy is set is a shielding boundary node, and the RRO sub-object is not deleted.

  FIG. 12 is a diagram illustrating an example of RRO sub-object deletion processing by the shielding boundary node in the present embodiment. In FIG. 12, domain 2 is designated as a shielding target area of route information. Further, the node 10D and the node 10F are shielding asymmetric nodes, and the node 10E is a shielding target node. When the node 10 </ b> F determines that the node is a shielding boundary node, the node 10 </ b> F deletes the RRO sub-object (E) to which a flag indicating that it is a shielding target is assigned and the flag.

<Effects of Embodiment 2>
According to the embodiment described above, each node can acquire normal route information in the shielding target area of the route information, as in the case of the first embodiment. Also, by setting the shielding target node and the shielding non-target node, each node can acquire route information excluding the shielding target node in the shielding target region outside the shielding target region of the route information.

[Embodiment 3]
Next, Embodiment 3 of the present invention will be described. The third embodiment has common points with the first embodiment. Therefore, the difference will be mainly described, and the description of the common points will be omitted.

  In the first embodiment, when a node in the shielding target range of the route information becomes the start point node, all the route information is deleted at the shielding boundary node in the shielding target range, and therefore an empty RRO is transmitted. become. Sending an empty RRO is a problem because it is a violation of the standard. In the present embodiment, this problem is solved.

<Constitution>
FIG. 13 is a diagram illustrating a network configuration example according to the present embodiment. FIG. 15 is an example when the shielding target area of the route information is set in units of domains.

  In the network 300 of FIG. 13, there are six nodes (nodes 30D to 30I). The node 30D, the node 30E, and the node 30F are included in the domain 2, and the node 30G, the node 30H, and the node 30I are included in the domain 3. The node 30D is a start point node. Here, the domain 2 is set as a shielding target area of the route information. In this case, the node located at the boundary of the shielding target region recognizes that the own node is the shielding boundary node using the domain attribute information (link management information database) of the link. Here, links within the domain are defined as intra-domain links, and links connecting the domains are defined as inter-domain links. Each node manages a link (link attribute) directly connected to its own node.

  The configuration of the shielding target node of the route information in the present embodiment is the same as the configuration of the node in FIG. 2 of the first embodiment.

<Operation example>
FIG. 14 is a diagram illustrating an example of a processing flow of a node in the shielding target area in the present embodiment. Here, description will be given mainly using the node 10F as an example. The same processing flow is used in the node 10D and the node 10E.

  In FIG. 14, the process from receiving the path establishment request (S3002) to deleting the shielding target route information (S3014) is the same as the processing flow (FIG. 4) of the first embodiment. However, when the start point node exists in the shielding target area of the route information, the route information is lost when the shielding target route information is deleted. Therefore, the node 30F, which is a node at the shielding boundary, adds a pseudo node (domain 2) representing the domain to be shielded as an RRO sub-object (S3016).

  FIG. 15 is a diagram illustrating an example of the RRO sub-object deletion process by the boundary node. When the node 30F determines that the node is a shielding boundary node, the node 30F deletes the RRO sub-object (D, E, F) to which the flag indicating that it is a shielding target and the flag are assigned. Further, the node 30F adds a pseudo node (domain 2) representing the domain to be shielded to the RRO sub-object. Thereby, it is possible to avoid creation of an empty RRO.

  After a predetermined process, the node 30F transmits a path establishment request to the next node (S3018).

<Effects of Embodiment 3>
According to the present embodiment, as shown in FIG. 15, this function is not implemented when the start point node exists in the shielding target domain and the deletion target setting is applied to all the nodes in the domain. In this case, an empty RRO is sent out. Sending an empty RRO is a violation of the standard, but this violation can be avoided by using this function.

  Further, the configuration of adding the pseudo node of the present embodiment to the RRO sub-object can be applied even when the start point node does not exist within the shielding target area of the route information.

[Embodiment 4]
Next, a fourth embodiment of the present invention will be described. The fourth embodiment has common points with the first embodiment. Therefore, the difference will be mainly described, and the description of the common points will be omitted.

  In the present embodiment, a method for realizing flexible shielding of route information without changing the RRO sub-object will be described.

<Constitution>
The network configuration of the present embodiment is the same as the network configuration example of FIG.

  Further, as a modification, a network configuration similar to that in FIG. 10 in the modification of the first embodiment may be used.

  FIG. 16 is a diagram illustrating the configuration of the nodes in the shielding target area of the route information according to the present embodiment. The nodes in the shielding target area of the route information according to the present embodiment are substantially the same as the configuration of the nodes in FIG. The node according to the present embodiment further includes a shielding target node database 1054. The shielding target node database 1054 only needs to be included in at least all nodes located at the shielding boundary. That is, a node that is surely not to be a shielding boundary node may not have the shielding target node database 1054.

  The shielding target node database 1054 is a database describing a list of nodes to be shielded.

  Unlike the first embodiment, the RRO processing unit 1030 does not assign a shielding target flag indicating that it is a shielding target.

  If the RRO processing unit 1030 determines that the own node is a shielding boundary node, the RRO processing unit 1030 compares the RRO sub-object list with the shielding target node database. As a result of the comparison, the RRO processing unit 1030 deletes a node that matches the node described in the shielding target node database from the RRO sub-object list.

<Operation example>
FIG. 17 is a diagram illustrating an example of a processing flow of a node in the shielding target area in the present embodiment. Here, description will be given mainly using the node 10F as an example. The same processing flow is used in the node 10D and the node 10E.

  In FIG. 17, the process from the reception of the path establishment request (S4002) to the path establishment request (S4018) to the next node is the same as the processing flow (FIG. 4) of the first embodiment. However, in this embodiment, it is not necessary to set a flag indicating that the node is a shielding target node. Further, in the present embodiment, when the shielding target route information is specified (S4012), the shielding target node database 1054 is used instead of using the flag indicating the shielding target node.

  FIG. 18 is a diagram illustrating an example of sub-object deletion processing by a boundary node. When the node 10F within the shielding target range determines that the node is a shielding boundary node, the node 10F refers to the shielding target node database 1054 and deletes the RRO sub-object (D, E, F).

<Effects of Embodiment 4>
According to the present embodiment, the shielding target node database 1054 is updated as needed without changing the RRO sub-object, thereby realizing shielding of route information while flexibly changing the shielding range of the route information. be able to.

<Modification>
Instead of preparing the shielding target node database 1054, an intra-domain topology database can be used.

  In GMPLS / MPLS, a routing protocol (Non-Patent Document 5, Non-Patent Document 6, Non-Patent Document 7, Non-Patent Document 8, etc.) for collecting connection information of nodes in a network is defined as a standard. Each node can obtain information on nodes located in the network by using this protocol. Since information related to areas can also be given to the topology database, if a different area value is set for each domain, processing for only one domain can be realized.

[Embodiment 5]
Next, a fifth embodiment of the present invention will be described. The fifth embodiment has common points with the fourth embodiment. Therefore, the difference will be mainly described, and the description of the common points will be omitted.

  In the present embodiment, a method for adding the configuration of adding the pseudo node of the third embodiment to the configuration of the fourth embodiment will be described.

<Constitution>
The network and each node of this embodiment have the same configuration as that of the fourth embodiment.

<Operation example>
FIG. 19 is a diagram illustrating an example of a processing flow of a node in the shielding target area in the present embodiment. Here, description will be given mainly using the node 10F as an example. The same processing flow is used in the node 10D and the node 10E.

  In FIG. 19, the process from the reception of the path establishment request (S5002) to the deletion of the shielding target route information (S5014) is the same as the processing flow (FIG. 17) of the fourth embodiment. In the present embodiment, after the occlusion target route information is deleted, a pseudo node (domain 2) representing the occlusion target domain is added to the RRO sub-object list as in the third embodiment.

  FIG. 20 is a diagram illustrating an example of sub-object deletion processing by a boundary node. When the node 10F within the shielding target range determines that the node is a shielding boundary node, the node 10F refers to the shielding target node database 1054 and deletes the RRO sub-object (D, E, F). Further, the node 10F adds a pseudo node (domain 2) to the RRO sub-object.

Claims (6)

A receiving unit that receives a path trace control message including path information related to a path used for data transfer from a start point node to an end point node from a previous node on the path;
When the own node is a boundary node located at the boundary of the route information shielding section on the path, the portion related to the route information shielding section of the route information included in the route trace control message received by the receiving unit is identified. An editorial department that edits in an impossible state,
The route trace control message after the editing, and a transmission unit for sending to the next node located on said path,
The route information includes a list having an identifier of a node through which the path passes and a flag indicating whether the node belongs to the route information shielding section,
The editing unit deletes a portion related to a route information shielding section from the route information, identifies a node belonging to the route information shielding section in the list based on the flag, and identifies an identifier of the identified node in the list Delete from <br/> relay node. A receiving unit that receives a path trace control message including path information related to a path used for data transfer from a start point node to an end point node from a previous node on the path;
When the own node is a boundary node located at the boundary of the route information shielding section on the path, the portion related to the route information shielding section of the route information included in the route trace control message received by the receiving unit is identified. An editorial department that edits in an impossible state,
A transmission unit that sends the edited route trace control message to a next node located on the path;
The route information includes a list having an identifier of a node through which the path passes and a flag indicating whether the node belongs to the route information shielding section,
The editing unit deletes a portion related to the route information shielding section from the route information, adds pseudo information about the route information shielding section to the route information instead of the portion related to the deleted route information shielding section, and adds the flag to the flag. A relay node that identifies a node belonging to the route information shielding section in the list and deletes the identified node identifier from the list . A storage unit that stores specific information of nodes belonging to the route information shielding section;
The editing unit, on the basis of the identification information storage unit, a relay node according to claim 1 or 2 to remove the portion relating to the route information shielding section from the route information. Link management information database that stores the domain to which the local node belongs and the domain to which other relay nodes connected to the local device belong,
Further comprising
The editing unit
Referring to the link management information database, determine whether or not the domain to which the own device belongs and the domain to which the second relay node that is the transmission destination of the control message matches,
When the domain to which the own node belongs and the domain to which the next-stage relay node device that is the transmission destination of the control message does not match, determine that the own node is the boundary node;
The relay node according to claim 1 or 2 . A link management information database for storing a domain to which the own node belongs and information indicating whether other relay nodes connected to the own node are within the shielding target area or outside the shielding target area of the route information;
The editing unit
Referring to the link management information database, it is determined whether the next-stage relay node device that is the transmission destination of the control message is outside the shielding target area of the route information,
When the next-stage relay node device that is the transmission destination of the control message is outside the shielding target area of the route information, it is determined that the own node is the boundary node;
The relay node according to claim 1 or 2 . When the own node is not the boundary node and belongs to the route information shielding section, the editing unit includes an identifier of the own node and the own node including the route information in the route trace control message received by the receiving unit. Add a flag indicating that it belongs to the occlusion section,
The relay node according to claim 1 or 2 .

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